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Solanum procumbens L. (Solanaceae) were extracted respectively with n-hexane, ethyl acetate, and methanol to obtain the corresponding extracts. The methanol-soluble extract was acidified by adding HCl 0.5M; this was followed by liquid-liquid partition with CHCl3 to afford CHCl3-soluble fraction. From this fraction, four compounds were isolated and identified as ergosterol peroxide (1), 9,11-dehydroergosterol peroxide (2), N-(N-benzoyl-L-phenylalanyl)-L-phenylalanol (3), and moupinamide (4). Their structures were elucidated based on the NMR spectroscopic analysis and comparison with the literature. All isolated compounds were first reported from S. procumbens.

Voltage source inverters (VSIs) with an LCL-filter are commonly used in practice, especially in microgrid systems. Exactly determining the control coefficients for the controller of a VSI with an LCL-filter is an important and challenging issue. However, existing LCL-filter-based inverter systems usually assume that all system parameters are determined accurately and remain constant over time, which is not true in real situations. Variations in the system parameters are known to possibly seriously degrade the performance of LCL-filter-based inverter systems. For efficiency and robustness, this paper proposes a simple and robust method for the generalized controller design of a three-phase VSI with an LCL-filter system that can address deviations in system parameters. The proposed method can be effectively used to design the controller of an LCL-filter inverter system for fixed and varying system parameters. Simulations and experimental results are presented to validate the correctness and effectiveness of the proposed design method.

In this paper, a general design method for multifunction converters using photovoltaic systems is proposed. With the proposed converter, the photovoltaic generator can provide flexibility, accuracy, and fast responses in both harmonic suppression and power injection modes in all cases of the grid-connected load. The controller for the proposed converter is designed based on the Lyapunov technique, along with the generalized algorithm for determining the global optimal values of the stability bounds. Therefore, the proposed converter can perform accurately and efficiently in the case of fixed system parameters as well as in the case of varying system parameters. Simulations and experimental results are presented to validate the accuracy and effectiveness of the proposed model and control strategy.